A Ukrainian woman gave a harrowing account of what is happening at Russian a "filtration camp" for people relocated from eastern Ukraine.

The unnamed woman told The Washington Post that, along with her family, she was taken from the besieged Ukrainian city of Mariupol to what Russian forces described as a "filtration camp" along Russia's border.

She told the Post that she was then photographed and fingerprinted before being told to hand over her phone so the Russians could download her data and record all of her contacts.

The woman told the Post that she faced multiple rounds of interrogations, including by the Russian security service FSB, before being brought to the Russian port city of Taganrog.

She told the Post that she eventually broke away from the group by claiming to Russian soldiers that she had a friend nearby in Russia who could house her and her family.

The Kremlin said on Monday that reports of Ukrainians being forcibly relocated are "lies," according to the Post.

But Ukrainian officials have accused Russia of forcing thousands of citizens from Mariupol — a heavily bombarded southern port city in Ukraine — to remote cities in Russia.

Mariupol City Council previously said Ukrainians had phones and documents checked, and were forced into camps by Russian soldiers.

The US Embassy in Kyiv also accused Russia of kidnapping thousands of Ukrainian children from the eastern Donbas region.

Mariupol has been a focal point of the humanitarian aspect of Russia's ongoing war against Ukraine.

The city has been constantly shelled by Russian President Vladimir Putin's forces, and proposed humanitarian convoys and corridors have been difficult to construct.